Centrosomes are vital mechanical hubs in cells that sustain load-bearing attachments to microtubules and orchestrate arrays of microtubules to support cell motility, nuclear positioning, mitotic spindle assembly, and chromosome segregation. Mutations affecting the ability of centrosomes to sustain or regulate attachments of microtubules are correlated with an increase in genome instability and progression of cancers. Despite this important role and the considerable forces that centrosome-microtubule interactions are thought to sustain in vivo, microtubule attachments to centrosomes have never been mechanically investigated in any organism. Consequently, the extent to which these interactions may be mechanically regulated has also never been investigated. In a collaborative project with the Asbury, Davis, and Agard labs, this work aims to reveal the molecular interactions by which centrosomes sustain, sense, and respond to forces transmitted by microtubules. Centrosome-microtubule interactions will be reconstituted in vitro and individually interrogated using a combination of single molecule laser trapping, total internal reflection fluorescence (TIRF) microscopy, and molecular cell biology techniques. Through the combination of biophysical expertise in the Asbury lab with the biochemical and structural expertise of the Davis and Agard labs, this proposal will determine the role of specific molecular components in sustaining and regulating attachments of microtubules to centrosomes more precisely and directly than has ever been done before. Revealing how centrosomes sustain, sense, and respond to mechanical forces will shed light on how these pathways fail in human diseases such as cancer and may ultimately lead to the identification of new chemotherapeutic targets.